GRIMSBY Town's first home game of the season ended in defeat as Coventry City took all three points away from Blundell Park.
After a scrappy first half with few moments of quality, the visitors took the lead three minutes after the hour in controversial fashion, with striker Marc McNulty's quick thinking seeing him play the ball into an unguarded net after the referee ruled a Town free kick had been taken and with goalkeeper James McKeown left stranded.
The Mariners never really recovered from that setback and Coventry made sure of their victory with 15 minutes to go, when right-back Jack Grimmer powered a header home from a corner.
James Berrett then became the second Grimsby player to be shown a red card so far this campaign as he was dismissed for a second bookable offence in the closing stages of the game.
The Town starting XI showed two changes from the victory at Chesterfield on the opening day of the season last week, with Luke Summerfield coming in for Sam Kelly and Ben Davies replacing the suspended Zak Mills.
McKeown began in goal, with Davies, Nathan Clarke, Danny Collins and Paul Dixon forming the defence.
Berrett, Mitch Rose, Summerfield and Siriki Dembele were the midfielders, with Sam Jones and Harry Cardwell in attack - the latter a late addition to the side after Scott Vernon had initially been named.
New signings JJ Hooper and Diallang Jaiyesimi were both named on the bench after joining the club in midweek, with Ben Killip, Sean McAllister, Karleigh Osborne, Tom Bolarrinwa and Jack Keeble also selected as substitutes.
Coventry arrived in Cleethorpes also looking to make it two league wins out of two, having beaten Notts County 3-0 in their opener last week.
Winger Jodi Jones scored all three of the Sky Blues' goals in that game and would look to be one of the main threats to the Town defence, along with strikers Stuart Beavon and McNulty.
Neither side was able to make much of an impression in the early stages, with Beavon's flicked header from a Grimmer cross for Coventry bouncing harmlessly through to McKeown in what was the first attack of note on eight minutes.
Jones had an attempt blocked for the Mariners after working an opening for a shot on the edge of the box, then Dembele was caught offside after Cardwell had flicked a header on.
The best moment of the game so far came on 16 minutes, when Dembele set off on a run at pace through the middle. The ball eventually came to Jones in the box but he could only drag a low shot wide of the far post.
Dembele won a corner on the right soon afterwards and Summerfield's ball from it was won by Clarke but visiting keeper Liam O'Brien was first to the defender's header across goal.
A foul on McNulty gave Coventry a free kick in a dangerous central position on 21 minutes but Jones' effort from it hit the Town wall before midfielder Liam Kelly volleyed the rebound wide.
A dangerous cross then came from Coventry's Jones after he skipped past Davies down the away left but Clarke was first to the ball, heading it clear.
Berrett hit a left-footed shot wide from 20 yards but chances were still proving hard to come by with the half-hour approaching, as both sides looked to play long balls.
A foul by Dixon gave the visitors a free kick inside the Grimsby half but when the ball from it was eventually played to the edge of the box, the left-back was in the right place to volley clear.
Another Coventry free kick came soon afterwards following a foul by Clarke but again, there was nothing to seriously trouble the Town defence as the referee blew for a foul on Jones as the kick was taken.
Stokes won a corner on the away left on 35 minutes but the ball from the flag was glanced away for a throw-in.
The Mariners were forced to do some defending on 39 minutes after a quik break led to a shooting chance for Coventry's Jones. McKeown dived to stop the effort, then Summerfield did well to get his head to the rebound.
A penalty appeal from the away supporters was waved away by referee Richard Clark after Jones went down, before a foul on the winger by Dixon was punished with a free kick and a yellow card, with Jones also booked for his reaction.
A low cross from Jones was cleared by Carke as Coventry appeared to be getting on top with half-time approaching.
One additional minute was signalled to be played at the end of the half and with no further chances created by either side, the game remained goalless at the interval.
No changes were made before the restart and Berrett was booked within seconds of play resuming for stopping an early Coventry free kick from being taken.
Jones won a corner for the visitors three minutes in but the ball from it was cleared and Town broke through Dembele before Davies was fouled just inside the Coventry half.
Good build-up play involving Jones and Rose on 51 minutes saw the ball go to Cardwell in the penalty area but the striker's low pull-back across goal was cut out.
At the other end, a good shot from Jones from 25 yards was pushed the ball over the bar by McKeown for a corner. The ball from the flag was headed back across goal by Peter Vincenti at the far post but it dropped out of play for a goal kick.
A shot from Beavon was blocked, before an excellent chance for the away side saw a number of players have shooting opportunities as the ball was passed around the box. Nobody took the chance though and it was lost when Vincenti fell over, with penalty claims waved away.
Coventry were starting to look dngerous but it was Town who had the next chance, with Jones rifling an effort over the bar from the left side of the penalty area.
The visitors had looked the most likely to open the scoring but when they did take the lead on 64 minutes, it was in controversial circumstances.
A Town free kick inside their own half was touched by Clarke with the intention of it being taken by McKeown but as McNULTY stepped in to take possesion, the referee ruled the kick had been taken by the defender and with McKeown stranded, the striker put the ball into the unguarded net.
Town protested that the free kick had not been taken but despite their arguments, led by McKeown, the goal was allowed to stand.
Hooper was sent on in place of Cardwell soon after the goal, before a good challenge by Collins saw him get a vital deflection on a shot to ensure his side did not go further behind on 70 minutes.
Jaaiyesimi was the next to be sent on for the Mariners, with Summerfield the man to make way for the loan signing from Norwich City.
The away side made their first change at the same time, with Dominic Hyam replacing Jordan Willis after the centre-back had gone down with an injury.
Collins had to concede a corner as Coventry attacked again on 75 minutes and when the ball was played from the flag, the visitors doubled their advantage as GRIMMER powered a header past the dive of McKeown, which could not be kept out despite the best efforts of Davies on the line.
Bolarinwa came on in place of Dembele with eight minutes to go, as Town looked to stage a late revival.
And they had a chance to pull a goal back when Jones had a shooting chance on the edge of the box but unfortunately for him and the Mariners, the effort flew over the bar.
Things were to get worse for Town with two minutes to go, as they were reduced to 10 men fo the second time in two league games. Berrett was the man to see red, as a poor challenge on Kelly resulted in him being shown a second yellow card.
Seven added minutes were signalled to be played and they passed without much incident as Coventry closed out their victory.
Town are next in action on Saturday, when they travel to Stevenage.
Town: McKeown, Davies, Dixon, Clarke (C), Collins, Berrett, Rose, Jones, Summerfield (Jaiyesimi 71'), Cardwell (Hooper 67'), Dembele (Bolarinwa 82').
Subs: Killip, McAllister, Osborne, Keeble.
Coventry City: O'Brien, Grimmer, Willis (Hyam 72'), McDonald, Stokes, Kelly, Doyle (C), Jones (Nazon 87'), McNulty, Vincenti, Beavon (Andreu 79').
Subs: Charles-Cook (GK), Pearson, Stevenson, Biamou.
Referee: Richard Clark
Attendance: 6,767 (1,357)